Thad, IPC-D-275, Para 5.3.1.4 Edge Spacing - states that "except for edge-board contacts, the minimum distance between conductive surfaces and the edge of the finished board shall not be less than teh minimum electrical spacing requirements plus 0.016in." Para 5.4.4 states that "the spacing between adjacent, non-land holes, shall be not less than the finished board thickness or the hole diameter, whichever is less." Regards, Gary Ferrari Tech Circuits (203)269-3311 Chairman - IPC-D-275 committee